Working Group Report on Future Research Directions in
Childhood Obesity Prevention and Treatment
August 21-22, 2007
Workshop Report (in-page links)
Background and Objectives Summary
of Childhood Obesity Prevention Panel Meeting Summary
of Childhood Obesity Treatment Panel Meeting Cross-cutting
Issues Recommendations for
Research in Childhood Obesity Prevention Recommendations
for Research in Childhood Obesity Treatment Cross-cutting
Research Recommendations Priorities for Research
References Background
and Objectives
Childhood overweight and obesity have reached epidemic proportions and
are major public health problems nationally and globally (1). Between
1970 and 2004, the prevalence of overweight almost tripled among U.S.
preschoolers and adolescents and quadrupled among children aged 6 to11
years (2). In 2003-2004, 17.1% of children aged 2 to 19 years were at
or above the 95th percentile of Body Mass Index (BMI) compared to 5-6%
in the 1970s, and these percentages are higher in non-Hispanic Blacks
and Mexican Americans (20.0% and 19.2%) than in Whites (16%) (2). Obesity
rates are also high among American Indian children with a prevalence estimate
of 22% for boys and 18% for girls (3). Currently, about 25 million U.S.
children and adolescents are overweight or obese (1, 4), and children
from families that are of low socio-economic status are disproportionately
affected.
Obesity during childhood has been associated with
numerous adverse effects including a variety of health complications such
as hypertension, dyslipidemia, left ventricular hypertrophy, atherosclerosis,
metabolic syndrome, type 2 diabetes, sleep disorders, and non-alcoholic
fatty liver disease (5-7) as well as psychological effects such as stigmatization,
discrimination, depression and emotional trauma. Obesity in childhood
also substantially increases the risk of being an obese adult (8). In
addition, adults who were obese during childhood have higher risk of developing
hypertension, dyslipidemia, metabolic syndrome, diabetes, and coronary
heart disease than those who were not obese during childhood (8).
These health consequences of childhood overweight and obesity add to
the burden of health-care costs. The annual U.S. obesity-attributable
medical expenditures were estimated at $75 billion in 2003 dollars (9-10).
Hospital discharges for obesity-associated diseases in youth aged 6 to
17 years increased more than three-fold from 1979-81 to 1997-99 (35 million
to 127 million) (11). Hospital charges of obesity-associated comorbidities
that required hospitalization of pediatric patients were higher than those
that were not obesity-associated (e.g., discharges with obesity as a secondary
diagnosis vs. those without for asthma cost $7,766 vs. $6,043; p<0.05),
providing a financial imperative for obesity prevention initiatives (12).
The development of obesity in childhood and subsequently in adulthood
involves interactions among multiple factors that may shape daily diet
and physical activity behaviors and increase obesity and cardiovascular
disease risks. These factors are personal (e.g., beliefs, attitudes, cultural
experiences, taste preferences, and dietary composition), environmental
(e.g., homes, schools, community, food availability and cost, built environment),
societal (e.g., cultural norms, advertising and food marketing, social
networks, technological developments, economics, public policy) and healthcare-related
(e.g., provider counseling and treatment, reimbursement), as well as physiological
(e.g., intrauterine and early life “programming”, appetite and satiety
mechanisms and regulation, adipose tissue metabolism, genetic predisposition)
(13).
In light of the recognition of childhood obesity
as a major public health problem with multiple etiological factors and
with comorbidities and their associated high health-care costs, numerous
health organizations and foundations (e.g., Institutes of Medicine, American
Academy of Pediatrics, American Medical Association, American Heart Association,
Robert Wood Johnson Foundation, and the National Institutes of Health
[NIH]) have called for a collective effort to combat the problem from
multiple fronts, including innovative cutting-edge research (1). To advise
the National Heart, Lung, and Blood Institute (NHLBI) and other NIH Institutes
on which research areas to stimulate to advance knowledge about effective
obesity prevention and treatment in childhood, NHLBI convened a Working
Group meeting on August 21-22, 2007. The objective of the Working Group
was to identify priorities for future research directions in childhood
obesity prevention and treatment. The Working Group meeting was sponsored
by NHLBI with co-sponsorship by the Office of Behavioral and Social Science
Research (OBSSR) and the Office of Dietary Supplements (ODS).
The Working Group was organized into a Prevention Panel, chaired by Dr.
June Stevens, Professor of Nutrition and Chair of the Department of Nutrition,
University of North Carolina, Chapel Hill; and a Treatment Panel, chaired
by Dr. Stephen Daniels, Professor of Pediatrics and Preventive Medicine,
University of Colorado School of Medicine, and Chair of the Department
of Pediatrics. Participants included leaders and representatives from
public and private academic and medical institutions with expertise in
a variety of health specialties, including pediatrics, preventive medicine,
bariatric surgery, nutrition and diet therapy, physical activity, epidemiology,
physiology, genetics, and research methodology, as well as staff from
NHLBI, National Institute of Digestive, Diabetes and Kidney Diseases (NIDDK),
National Institute of Child Health and Development (NICHD), National Center
for Research Resources (NCRR), National Cancer Institute (NCI), OBSSR,
ODS, and United States Department of Agriculture (USDA).
The Prevention Panel focused on research priorities to prevent excess
weight gain in children and adolescents. The Treatment Panel focused on
research priorities for treatment of obesity which has already developed
in children and adolescents. Panel members reviewed the state of the science,
and identified many opportunities for research in childhood obesity prevention
and treatment. Topics discussed included behavioral and lifestyle interventions
for childhood obesity prevention and treatment, pharmacologic and surgical
treatment of severely obese youth, need for multi-level multi-component
interventions, opportunities to advance research on the effects of the
built environment, use of theoretical models and conceptual frameworks
in the design of interventions, approaches for obesity prevention and
weight loss treatment interventions for low socioeconomic status and minority
populations, design and methodological approaches to make interventions
more potent, and translation of promising childhood obesity prevention
and treatment research into both clinical and community settings. Participants
provided recommendations on how to advance knowledge through both observational
and intervention studies.
The panels were charged to identify priorities for future research directions
in childhood obesity prevention and treatment based on the following four
criteria: scientific importance of the research question, potential likelihood
of public health impact, likelihood of not being addressed by other funding
entities, and feasibility and timeliness. This report is a summary of
the Working Group meeting and the recommendations from the Working Group’s
two panels.
Back to top
Summary of
Childhood Obesity Prevention Panel Meeting
• Overview of Pediatric Obesity Prevention
Research
Prevention research, in contrast to treatment research, focuses on entire
populations or a subpopulation of children to decrease the number who
become overweight or obese and to reduce additional weight gain in those
who may already be overweight. Prevention research is concerned about
intervention sustainability and maintenance of intervention effects. The
Working Group discussed recent reviews of pediatric obesity prevention
research (14-19) and noted many limitations in research designs and outcomes.
For example, a Cochran review (15) of 22 randomized controlled trials
concluded that there was not enough evidence from trials to prove any
one program or approach can prevent obesity in children or adolescents.
Twelve of the 22 studies were short-term (<12 months), of which 8 focused
on combined diet and physical activity interventions and found no intervention
effects on BMI. The other 4 studies focused on single interventions (i.e.,
physical activity/TV reduction time), but only 2 found significantly lower
BMI in the intervention group compared to the control group (20-21). Of
the 10 longer-term studies ( ≥ 12 months), only 2 reported significantly
lower BMI or fat skinfolds in the intervention compared to the control
group (22-23). Other reviews by Flynn et al. (16) and Bluford et al. (17)
reported a paucity of studies that addressed obesity prevention in certain
subgroups of children (e.g., preschoolers, minorities, males, and immigrants).
The Working Group noted the need for transdisciplinary studies that separately
test efficacy, effectiveness and translation/dissemination. However, given
the urgency of finding solutions to the problem of childhood obesity,
it was recommended that these different types of research proceed simultaneously
rather than following a strict trajectory from efficacy to effectiveness
to translation in discrete, sequential steps (24).
• Theoretical Models in Childhood Obesity
Prevention
Theoretical models and conceptual frameworks that have been used in childhood
obesity prevention research include the Transtheoretical Model (25), Health
Belief Model (26), Social Cognitive Theory (27, 28), and Socio-ecological
Models (29). In most cases these models and theories have provided the
bases for studies that intervene on a select number of modifiable variables.
However, theoretical models have accounted for less than 50% of the variance
resulting from behavior change interventions (30). The Working Group noted
that behavior change is highly variable, sensitive to initial conditions,
and non-linear, and involves multiple interactions with, and influences
from, the social and physical environments (30, 31). One proposed approach
presented at the working group meeting stemmed from the observation that
since behavior change is often non–linear, one could consider principles
from “chaos” and self-determination theories as a framework for conceptualizing
change. Motivational interviewing represents a clinical strategy that
is consistent with these theories, as it can help induce epiphanies for
individual behavior change (30). The Working Group concluded that theoretical
and conceptual frameworks must be used, including innovative frameworks
and models from other health fields (e.g., substance abuse literature)
in designing interventions for pediatric obesity prevention and treatment.
However, more research is needed to assess the potential for various behavioral
models to contribute to obesity prevention (31-33) and to potentially
develop new theoretical models or modify existing models for greater utility
in obesity research.
• Environmental
Interventions
The environments of children include the home, child-care settings, school,
community, recreational facilities, and community and transportation infrastructure.
Studies on environmental correlates of children’s eating and physical
activity behaviors are mostly cross-sectional and thus cannot provide
causal inferences between the environment and behavior or BMI. For example,
if it is observed that people who are on a walking track have lower BMIs,
we don’t know if walking on the track leads to lower BMIs or whether those
with lower BMIs simply choose to use a walking track. However, such studies
help to identify environmental determinants of obesity, targets for interventions,
and relationships of the built environment to physical activity and eating
behaviors. For example, the home environment has shown that children who
watched less than 2 hours of TV per day had a significantly lower average
BMI z score than children who watched more than 2 hours per day (BMI z
scores of 0.22 vs. 0.73, respectively; F[1,152] = 5.0, p < .03). (34).
In one intervention trial, increases in the number of physical activity
equipment, infrastructural changes made to playgrounds, and added supervision
in middle school gymnasiums resulted in increased physical activity of
middle school students (35). In an observational study, proximity to recreational
facilities and programs was associated with higher total daily physical
activity in children (36). In a study of 201 parents of children aged
4 to 17, active commuting (i.e., walking or bicycling) to school was higher
in more walkable neighborhoods compared to less walkable neighborhoods
(25% vs. 11%) (37). Other studies have found direct associations between
neighborhood walkability and children’s physical activity levels (38,
39). Associations between the environment and eating behaviors have also
been reported. Distance to the nearest food store was associated with
greater preference for vegetables (z = 2.32, p = 0.020) (40). The Working
Group called for observational studies that examine the association between
the built environment and BMI as well as diet and physical activity behaviors,
and intervention studies that assess whether larger-scale environmental
changes (e.g., improving quality of parks and access to healthful foods,
changing transportation systems such as trails, sidewalks, and crosswalks)
improve physical activity and eating behaviors and reduce rate of weight
gain in youth. Research is also needed for both individual-level and environmental-level
interventions and studies that take advantage of the changes in the built
environment as natural experiments that can be used with an appropriate
evolutionary component to evaluate the utility of these alterations. When
it is not feasible to evaluate changes in the built environment, then
rigor can be improved with prospective studies that evaluate changes in
behavior or BMI when families move to different neighborhoods, as well
as with studies that assess changes in behavior or BMI among children
living in neighborhoods with contrasting food and built environment attributes.
• Multi-level
Interventions
A review of 147 intervention studies by Flynn et al. (16) concluded that
there have been a paucity of studies testing population-based and multi-level
intervention approaches and that studies that focused on modifying the
nutrition and physical activity environments lacked adequate methodological
rigor. Very few studies conducted interventions in community or home settings
or both, involved stakeholders in program implementation and evaluation,
or intervened on preschool children, immigrant populations and males.
Few interventions focused on environmental change. In a review of 38 school-based
studies by Centers for Disease Control and Prevention Task Force (14),
only 10 studies were judged to have adequate methodology to be considered.
Many of those studies showed some behavioral and or weight changes in
the hypothesized direction favoring the intervention group; however, the
interventions and measures used were so varied that the CDC Task Force
could not determine which approaches to school-based interventions were
effective, defined as weight loss of ≥ 4 lb after ≥ 6 months of
intervention, and thus did not develop specific recommendations based
on these studies. The Task Force concluded that more evidence is needed
before recommendations could be made concerning effective school-based
interventions to control overweight or obesity. Other reviews of childhood
obesity prevention interventions (15, 16) have also found a lack of evidence
that identified the intervention components, duration, intensity,
and settings most effective for childhood obesity prevention. The studies
also lacked appropriate evaluations of mediating and moderating variables
that could be important in determining changes in behavior.
From their review of the literature, the Working Group concluded that
the existing body of research provides no definitive answers concerning
the optimal intervention approaches or settings for obesity prevention.
There is a substantial gap between the call for multi-level interventions
by such groups as the Institute of Medicine (1) and evidence to guide
what are believed to be the most promising interventions. The Working
Group recommended more research that included multi-level and multi-component
interventions, recognizing the additional challenges presented by such
studies. In particular, the role of parents and other family members,
as well as parental lifestyle factors and their effects on child body
weight, deserves more study and should be incorporated into interventions
to change children’s behaviors. It was apparent that school-based interventions
must provide students with a larger intervention dose than interventions
currently deliver. This could be accomplished through combining school-level
interventions with interventions delivered in other settings. Such strategies
could link schools with families, community organizations and health care
providers to change the physical activity and food environments fostering
a “behavior-environmental” synergy. The Working Group recommended that
more research should be targeted at the environmental levels and that
policy changes at multiple levels be studied carefully as facilitators
of change. Multi-level and multi-component interventions should be accompanied
by process evaluation and cost-effectiveness analyses, and aim to evaluate
the effects of the intervention components separately and in combination.
• Design Issues in Childhood Obesity
Prevention
The Working Group made the following suggestions to provide the information
needed to increase intervention potency and improve scientific rigor in
childhood obesity prevention studies (24): 1) Investigators should describe
the intervention as it was actually delivered, including midstream changes
and fidelity measures. Adaptive intervention designs are needed that include
a priori plans for modifying the intervention based on interim evaluations.
Also needed are statistical methods that are appropriate for this approach;
2) For group randomized designs (the unit of assignment and analysis is
the group), investigators must use appropriate analyses and account for
intraclass correlations in their sample size calculations. In a review
of the literature on 59 group randomized designs, 54% used appropriate
analyses, 25% a mixture (unit of analysis was both the group and individual)
and 20% used inappropriate analyses (individual was used as the unit of
analysis in a group randomized design) (41, 42); 3) Investigators should
carefully consider their outcome measures.
Percent body fat derived from an appropriate prediction equation may
be a better outcome measure than BMI, especially if changes in activity
are specific targets of the intervention. Whenever possible, investigators
should use objective measures rather than self reported measures. When
self-reported measures must be used, they should be prominently identified
as such and the potential for differential bias between the control and
intervention groups addressed; and 4) Investigators should consider conducting
“evidentiary studies” (24), before undertaking a large randomized trial.
Evidentiary studies break down a planned randomized trial into pieces
and test selected components in a design that is adequately powered. The
outcome of an evidentiary study is never the same as that planned for
the larger randomized trial and is usually more modest and easily changed
than the primary outcome of the larger trial. For example, prior to conducting
a multi-component school-based randomized trial aimed at changing student’s
percent body fat through an intervention that includes, as one component,
increased physical activity in physical education (PE) classes, an evidentiary
study might assess activity in PE using direct observation or accelerometry
following implementation of that component of the intervention. A social
marketing component planned as part of the same randomized trial might
assess impact on targeted attitudes using a questionnaire. Evidentiary
studies are larger and more fully powered than pilot or feasibility studies,
and often assess mediating and process variables. The Working Group recommended
that evidentiary studies be conducted of natural experiments and quasi
experimental designs be used to generate hypotheses in addition to randomized
controlled trials. Studies could be in two phases: phase 1 evidentiary
studies followed by larger-scale phase II studies.
• Translational Issues in Pediatric
Obesity Prevention Research
Translation research has been categorized into two phases: basic research
to clinical science (Translation 1), and clinical science to clinical
practice and in community settings (Translation 2) (43). The Working Group
appreciated that theory provides the foundation for the design of behavior
change programs. Since the basic research in this area has not been highly
predictive of behavior, thereby placing limits on what the ensuing interventions
might achieve, the Working Group believes basic research must be supported
in this area. As new theoretical ideas and models show promise in basic
research, interventions based on them can be tested with greater chances
for effectiveness. However, at this point in the obesity epidemic, the
Working Group believed that for childhood obesity prevention, Translation
2 is the more important of the two.
Translation 2 research studies can examine factors associated with implementation
of proven approaches, and can test various approaches to improving implementation
of proven interventions in practice. Although substantially more research
is needed in this area, successful translation of research findings into
practice would seem to entail researchers addressing barriers to dissemination
and implementation in their intervention designs. In addition, when designing
multilevel intervention programs, researchers could use systems and socio-ecological
models that attend to the “connectedness” and integration across program
components and levels (43, 44). The Working Group called for research
that identifies successful strategies that can be used to translate research
into action in a diverse array of individuals and settings and via a multitude
of channels. Researchers were encouraged not to consider only the use
of very low-cost strategies for translation when those strategies are
unlikely to be successful. Rather creative strategies should be devised,
tested and evaluated for their cost-effectiveness. Obesity prevention
research should draw from research advances in other disciplines (e.g.,
basic sciences, behavioral or environmental) to more appropriately test
potential novel interventions and speed effective interventions into clinical
practice and public health use.
Back to top
Summary of
Childhood Obesity Treatment Panel Meeting
• Identification and Treatment of Pediatric
Obesity
The Working Group discussed the Expert Committee Recommendations on the
Assessment, Prevention and Treatment of Child and Adolescent Overweight
and Obesity (45). Expert Committee recommended a new classification to
replace the definitions for overweight and “at risk of overweight:” Children,
ages 2 to 18 years, with a BMI ≥ 95th percentile for age and sex should
be considered obese. Children with BMI ≥ 85th percentile but < 95th
percentile for age and sex should be considered overweight. This replaces
“at risk of overweight.” The use of the 99th percentile of BMI for age
cut-offs was recommended (for severely obese) to allow for improved accessibility
of the data in the clinical setting and for additional study (45).
The Working Group reviewed the literature on childhood obesity treatment
research and noted there is a paucity of research on treatment as well
as numerous methodological limitations of studies that do exist, including
small samples sizes that are often convenience samples and therefore not
representative, wide ranges of age groups with no stratification by age
or risk, and short intervention and follow-up periods (usually less than
12 months). The prevalence of multiple risk factors increases as the BMI
percentile increases, and severe obesity is associated with increased
risk of co-morbidities and resistance to sustained weight loss (46). However,
it remains unknown why some pediatric patients with obesity are at higher
risk of certain complications compared to others.
• Overview of Pediatric Obesity Treatment
Research
Treatment of obesity in children and adolescents has many similarities
to treatment in adults, including available modes of treatment (i.e.,
behavioral, pharmacologic and/or surgical). However, children differ biologically,
behaviorally and socially from adults as well as from stage of growth
and biological and developmental age. Weight maintenance (until BMI is
< 85 th percentile) with behavioral treatment is recommended for overweight
and obese children, ages 2 or more years who have no health complications
(e.g., hypertension or dyslipidemia), and weight loss is recommended for
those with health complications (45). Differences in the treatment of
obesity in youth compared to adults pertain to special circumstances in
children’s physiology (e.g., growth, pubertal development, fat distribution,
comorbidities, side effects from medications), psychosocial factors (e.g.,
cognitive development, motivating factors, body image, short-term attention
span, risk-taking behaviors, lack of concern about health), and environmental
influences (e.g., family control, schools, food environment, changing
peer groups, effects of advertising, availability of sedentary opportunities).
The mainstay of obesity treatment in children and adolescents is to change
behaviors related to energy balance. Behavior change in this group is
generally safe and, when effective, is generally sustained longer than
in adults (47, 48). Pediatric obesity treatment research can also be informed
by successful prevention research.
The Expert Committee’s recommendations include a staged approach to treatment
and weight maintenance or weight loss goals (45). Stage 1 – “Prevention
Plus” includes family visits with physician or health professional and
lifestyle/behavioral treatment; Stage 2 - Structured Weight Management:
stage 1 recommendations plus more structure and support including individual
or group follow-up visits with a dietitian and exercise therapist that
include self-monitoring, goal setting and rewards, and monthly individualized
treatment. Stage 3- Comprehensive and multidisciplinary approach that
includes increased intensity and frequency of stage 2 approaches; structured
behavioral program with diet and physical activity goals; and weekly group
sessions for 8-12 weeks plus follow-up. Stage 4 - Tertiary care intervention
for severely obese youth includes use of medications (e.g., sibutramine,
orlistat), very-low-calorie diets and/or surgical approaches in combination
with behavioral treatment (45). However, within this framework, there
is still a substantial number of research questions that must be addressed.
The Working Group noted that more information is needed on best approaches
for behavioral treatment in obese children and adolescents. For example,
what is the best intervention content and how should it vary by age? How
should family members be involved and should the focus of the intervention
be on the child alone, parent alone, or entire family? What predicts the
likelihood of success of treatment? How should treatment programs be designed?
Who are the optimum team members?
A second option for childhood obesity treatment is the use of pharmacologic
agents. However, there are only two drugs approved by FDA specifically
for obese adolescents, and their long-term safety is unknown: orlistat
(approved for age 12 and older) and sibutramine (approved for age 16 and
older). Orlistat inhibits fat absorption and is associated with gastrointestinal
side effects including steatorrhea, bloating, cramping, and fecal incontinence.
Sibutramine is a monoamine reuptake inhibitor that enhances adrenergic
serotonergic and dopaminergic signaling in the brain and suppresses appetite.
Side effects include increases in blood pressure and heart rate. A third
option for treatment of pediatric obesity is bariatric surgery. Two surgical
procedures are being offered: Gastric bypass with Roux-En-Y anastomosis
and adjustable gastric banding.
The Working Group concluded that much more information is needed to address
obesity treatment in children and adolescents.
• Settings for Pediatric Obesity Treatment
and Research
The Working Group noted that the recommendations of the Expert Committee
have implications for treatment in various settings. In a primary care
setting, the goals include BMI screening and early identification of overweight
and mildly obese youth, support of clinical practice changes to enhance
identification and timely treatment of overweight children, and stage
1 “prevention plus” interventions and follow-up that emphasize small specific
lifestyle changes. In school and community settings, the goals should
be early screening to identify children who are mildly-to- moderately
obese followed by stage 2 “structured weight management” interventions
that are comprehensive, of longer duration, and linked with a health-care
practitioner and team. In referral centers, stage 3 “comprehensive, multidisciplinary
team of interventionists” and stage 4 “tertiary care intervention” should
be the goal for moderate to severe obesity, especially when comorbid conditions
are present.
The Working Group noted that although there are recommendations for treatment,
they are based on insufficient scientific data. They recommended randomized
controlled treatment trials testing efficacy and effectiveness of tailored
intervention approaches with attention paid to participant characteristics
(e.g., severity of weight status, age, presence of risk factors), sufficient
intervention intensity and duration, and including formative and process
evaluations. The Working Group emphasized the need for studies that have
adequate power and that stratify participants based on weight status;
include diet and physical activity interventions that are tailored to
severity of obesity status, risk factors, and phenotypes (e.g., hypertensives);
and include parent-centered interventions, particularly for younger patients.
The Working Group noted that there is a paucity of research on how to
implement pediatric obesity treatment in the primary care setting, and
concluded that research is needed to develop a model of care for treatment
of childhood obesity in the primary care setting, analogous to the chronic
care model for treatment of chronic diseases in adults (49).
The Working Group discussed reviews of the literature on skills of health
professionals for treating pediatric obesity. Training is needed of health
care providers in behavior change as an integral part of the model of
care for obesity treatment. In a study by O’Brien et al. (50), in a large,
primary care practice (urban, minority, 90% Medicaid), pediatric residents,
nurse practitioners and faculty physicians documented obese status in
only 53% of obese patients and only 15% were counseled to increase physical
activity (50). A Cochrane review (51) of interventions for treating childhood
obesity concluded that “there is a limited amount of quality data on the
components of programs to treat childhood obesity that favor one program
over another. Further research that considers psychosocial determinants
of behavior change, strategies to improve clinician-family interaction,
and cost-effective programs for primary and community care is required.”
• Behavioral and Lifestyle Interventions
to Treat Obese Children
The Working Group discussed family-based studies and noted that parent’s
weight loss predicted child’s weight loss in a family-based behavioral
weight control study (52-54). Treating parents alone was associated with
a reduction in percent of overweight children [-9.5% (0.4 BMI Z score;
P=0.003) in the parents-only group vs. -2.4% (0.1 BMI Z score) in the
parents–children group] (53). However, few studies have reported on family
relationships or family outcome measures (54). Self-monitoring of target
behaviors was positively associated with weight loss (average of 30 kg
for an average of 5.5 years) in adults (55). Such studies in children
are limited. The Working Group called for research to identify strategies
to enhance self-monitoring practices and determine their association with
successful weight management in children and adolescents.
The Working Group made three research recommendations for behavioral
and lifestyle interventions to treat obese children: 1) identify family
dynamics which predict success of certain interventions and changes in
family dynamics and relationships that are associated with favorable treatment
outcomes; 2) identify utility of and methods for promoting self-monitoring
of target behaviors by parents and children; and 3) investigate strategies
to effectively recruit families into family-based interventions.
• Pharmacologic Treatment of Childhood
Obesity
The Working Group reviewed studies that used orlistat in treating obese
adolescents and noted that in general there were small but significant
reductions in BMI after one year but no significant differences in blood
glucose, insulin, or lipids compared to controls on placebo. In one randomized
controlled trial, orlistat was found to reduce BMI by 5% in 26% of children
who took the drug compared to 15% of those on placebo (56). Gastrointestinal
tract adverse events were more common in the orlistat than placebo group
(56, 57).
The Working Group reviewed the trials using sibutramine. Two 6-month
and one 1-year controlled studies of sibutramine found significant weight
loss (e.g., 7.2 kg vs. 3.2 kg), and improvements in insulin, HDL, and
triglycerides compared with placebo (58). However, adverse effects on
blood pressure and pulse rate were noted (58-60) and long-term cardiovascular
effects of sibutramine are unknown.
The Working Group discussed many issues related to studies of pharmacologic
agents to treat pediatric obesity. Important unanswered questions include
the following: Which patients (e.g., age, BMI level, presence of comorbidities)
are the best candidates for pharmacologic intervention? Should pharmacologic
studies be limited to adolescents? What behavioral interventions work
best in conjunction with pharmacologic treatment? What is the appropriate
comparison (e.g., placebo, behavioral intervention, bariatric surgery,
other drugs)? What is the appropriate duration of treatment to best assess
efficacy and safety? What constitutes sufficient evidence to recommend
pharmacologic therapy in clinical practice? What information do third
party payors need to determine what treatments to cover for pediatric
obesity?
The Working Group noted that greater prevention and treatment efforts
are needed for severely obese youth (approximately 4% of children and
adolescents currently). Longer-term studies of severely obese adolescents
combining pharmacotherapy and lifestyle modification are also needed.
Treatment of severely obese youth is unlikely to be successfully implemented
in the primary care setting alone and would require interventions in multiple-settings.
• Surgery and Devices to Treat Severely
Obese Adolescents
About 5% of U.S. adults (>14 million) and 4% of children and adolescents
(>2 million) are severely obese (BMI ≥ 40 for adults and ≥ 99th
percentile for children). Severe obesity in children is associated with
comorbidities for cardiovascular diseases (e.g., hypertension, hyperinsulinemia,
Type 2 diabetes). Bariatric surgery is increasingly being used in both
adults and children. From 1996 to 2002, U.S. population-adjusted rates
of bariatric surgery in youth (<20 years old) increased from 0.23 per
100,000 to 73 per 100,000 (61). A report on bariatric surgery in adolescents
identified retrospective studies suggesting that both gastric bypass and
gastric banding led to sustained and clinically significant weight loss
compared to non-surgical approaches in adolescents (62). However the cost
of bariatric procedures was high, ranging from $8,650 to $25,000 per surgical
treatment. A limited number of studies (62-64) have found improvement
in depressive symptoms, quality of life, type 2 diabetes, cardiovascular
risk factors, and obstructive sleep apnea with bariatric surgery. Adverse
events and complications from bariatric surgery are lower in adolescents
compared to adults, but the long-term effects are unknown. Weight regain
is also known to occur in some patients post surgery.
The Working Group concluded that there are many unanswered questions
regarding the efficacy of bariatric surgery in adolescents. Should patients
be selected for surgery based on age, BMI, comorbidities, psychological
and/or quality of life issues? Are there unique benefits or risks of surgical
weight loss procedures in adolescents compared to adults? Is there any
effect of weight loss procedures on linear growth and bone health? What
are the long-term psychosocial issues? Is there a way to predict which
procedures are of greatest benefit and lowest risk for various types of
patients? What are the predictors of success or failure and how efficacious
are combination approaches (e.g., surgical treatment with pharmacotherapy;
or surgical treatment with environmental and behavioral interventions)?
Does the mechanism of weight loss differ from mechanisms of comorbidity
resolution? How will decisions regarding insurance coverage be determined?
• Translational Issues in Pediatric
Obesity Treatment Research
The Working Group discussed issues related to the translation of childhood
obesity treatment research and concluded that research in pediatric obesity
treatment has been slow and has not provided adequate information for
practitioners. The Cochrane Effective Practice and Organization of Care
(EPOC) Group reviewed 18 studies and noted: “the heterogeneity and generally
limited quality of identified studies make it difficult to provide recommendations
for improving health professionals’ obesity management. At present, there
are few solid leads about improving obesity management, although reminder
systems, brief training interventions, shared care, inpatient care and
dietician-led treatments may all be worth further investigation. Further
research is needed to identify cost-effective strategies for improving
the management of obesity (64).”
The Working Group recommended the following research that would be relevant
to translation into practice: 1) clinical studies to develop and evaluate
effective strategies for getting pediatric care providers to calculate,
plot and track adiposity indicators (e.g., BMI percentile, waist circumference),
and to initiate discussions regarding treatment for overweight children
and their families; 2) development and evaluation of effective strategies
for dissemination and implementation of evidence-based overweight treatment
guidelines into pediatric care practices; 3) development and evaluation
of effective counseling strategies for use by pediatric care providers
when implementing treatment recommendations for overweight children and
their families; 4) identification and evaluation of resources, services
and care strategies that are effective as adjuncts to healthy lifestyle
counseling and medical/surgical therapy within pediatric care settings
for overweight children and their families, and 5) support of basic science
research to evaluate the mechanisms of the development of obesity and
its comorbidities that can serve as targets for new interventions. These
targets, should they be studied to evaluate their effectiveness, may help
develop new pharmacologic and surgical approaches to obesity treatment.
Back to top
Cross-cutting
Issues
• Low Socioeconomic Status and Minority
Issues
The Working Group discussed the childhood obesity problem as it relates
to socio-economic status (SES) and race/ethnicity. As previously noted,
there is excess risk of obesity among children in ethnic minority populations,
and some of this excess may relate to ethnic group differences in socioeconomic
status (65). The relationship of SES and obesity in children and adolescents
may not be consistent by age and gender or over time (66). For example,
the prevalence of obesity may be higher in African American and Mexican
American adolescents in middle to high income families than among those
in lower income families, at least among girls, whereas the more typical
inverse gradient (less obesity among higher income families) may be observed
in white children (66).
The Working Group noted that there are many unanswered questions regarding
how race/ethnicity and SES predispose children to becoming obese (67).
For example, what food-intake behaviors or child feeding practices that
might contribute to excess weight gain are specific to or more prevalent
in these population groups? What is the relative importance of cultural
attitudes and beliefs regarding obesity and its effects versus the physical,
social, economic, and policy environments of children and their families?
Why is time spent watching television so much higher among African American
and Hispanic children than among whites? Other issues, not specific to
minority children but possibly different or of greater relative importance
include parental attitudes about eating, physical activity, and weight
control and family environments for eating and physical activity as well
as how the fear of crime affect children’s access to physical activity
resources and healthy foods. Consideration should also be given to psychosocial
factors and their role in obesity and development of cardiovascular diseases.
Additional variables possibly associated with excess risks in minority
and low income groups include adult role models, the socio-political contexts
in which ethnic minority and low-SES families live and work, food and
economic insecurity, discretionary income as a proportion of total income,
coping styles, access to physical activity resources and to healthy foods,
costs of healthy versus unhealthy food choices, level of resources available
to schools, and media, technology (65, 67) and neighborhood
environments (e.g., crime and fear of crime).
The Working Group recommended research to inform population-based approaches
for the prevention of childhood obesity in high-risk populations—research
targeted specifically to these populations, in addition to research applicable
to ethnically and socio-economically diverse populations. Research on
intensive, individually tailored “high-risk” strategies for obesity prevention,
which may be analogous to the types of approaches used for obesity treatment,
should also be emphasized in the populations most disproportionately affected
(African Americans, Hispanics, Native American Indians, Asian/Pacific
Islanders, rural and low-income children in general). However, individually-oriented
approaches without companion approaches at the environmental or community
level may not be effective and could be counterproductive (65). Research
issues of particular interest include effective strategies for community
engagement and community-based participatory research, how to incorporate
more ethnographic or other types of qualitative research to better understand
factors that might facilitate or hinder obesity prevention in high-risk
populations, and how to expand the paradigms used to develop obesity research
so that intervention approaches take into account population-specific
historical legacy, core values, and family and community life issues (68).
The Working Group recommended various methods to increase recruitment
of more minorities into research studies including community engagement
in study design and implementation, fostering trust and being careful
not to overwhelm enrollees, providing solutions to barriers to participation
(e.g., by providing transportation, child care and parking vouchers),
creating communities within the study population, and more community-based
participation in research with bi-directional partnerships between researchers
and communities. The Working Group suggested that interventions be initiated
in preschool through high school, targeting parents, especially obese
mothers, as well as children’s diet and physical activity behaviors, and
that considerations be given to recruitment-related cultural and economic
factors as well as social networks associated with food and physical activity
among ethnic/racial groups at risk for obesity.
• Gene-environment interactions
The Working Group discussed interactions between environmental and genetic
factors that lead to phenotypic expressions of obesity, and noted that
genetic variants associated with childhood obesity, and type 2 diabetes
as well as family association studies have been reported in the literature
(69,70). It is anticipated that better understanding of the genetic and
physiologic contributions of obesity will be forthcoming. The Working
Group noted that some patients do better with certain interventions than
others. Genetic markers of obesity susceptibility may be used to target
individuals for a specific intervention or treatment. Conducting genome-wide
association studies with childhood obesity could identify genetic factors
and mechanisms, and pharmacogenomics could provide a basis for future
personalized medicine approaches. The Working Group suggested that future
research in childhood obesity collect DNA samples to examine genetic variants
and their associations with obesity and risk for comorbidities.
• Methodological Issues in Pediatric Obesity
Prevention and Treatment
Research from the field of engineering has demonstrated that study designs,
when appropriately implemented, can isolate effects of individual program
components and help fine-tune interventions with an efficient use of samples
of subjects (71). Innovative research designs such as the Sequential Multiple
Assignment Randomized Trial (SMART) have been instrumental in helping
to develop “adaptive interventions” that are optimally tailored to individuals
and individual progress over time (71-74). The Working Group discussed
various methodological approaches and analyses to making interventions
more potent. These include using missing data to make causal inferences,
modeling of phenomena that have complex patterns of change over time and
relating them to other phenomena, modeling complex growth patterns in
intensive longitudinal data (e.g., data collected via PDAs, actigraphs)
(72, 73), combining expensive biological/instrument-gathered observations
with cheaper self-reports for improved validity while conserving resources,
addressing key research hypotheses by obtaining the more expensive measures
on a small subset of study participants, using reliable and valid measurements
and multilevel analysis, employing integrating latent variable models
and multilevel models, and using partial factorial designs (74-76).
The Working Group noted that appropriate research designs are needed
to build innovative and potent interventions. They recommended interdisciplinary
methodological perspectives (e.g., statistics, biostatistics, psychometrics,
education, economics, and qualitative method) be included in research
and collaboration between methodologists and prevention/treatment scientists
to conduct methodological research within the context of childhood obesity
prevention and treatment research.
Back to top
RECOMMENDATIONS
FOR RESEARCH IN CHILDHOOD OBESITY PREVENTION
MAJOR THEMES
Enhanced Understanding of the Influences
on Children’s Diet, Physical Activity and 0besity
- Conduct observational and experimental research to test new ideas
and develop new models of factors influencing children’s diet, physical
activity and obesity, including environmental, social (family and peer),
psychological, biological, and genetic factors. Studies integrating
behavioral with biological and genetic factors are particularly needed
in light of many recent advances in genetic and biological science in
this area.
- Identify specific modifiable factors in children’s built environment
that can make a justifiable difference in children’s ability to be more
active.
- Identify environmental and policy determinants of obesity and health
behaviors (characteristics of neighborhood, schools, child-care centers,
playgrounds; effects of fast food, fresh food markets, TV and other
electronic media, and food marketing), as well as factors related to
maintenance of a healthy weight over time.
- Identify critical periods for obesity development (e.g., factors associated
with excess weight gain throughout childhood; CVD risk evaluation in
the transition from childhood obesity to adult CVD in existing cohort
studies).
- Increase use of prospective and quasi-experimental designs to improve
causal inference for environmental and societal variables.
Obesity Prevention Interventions in Young
Children
- Test studies of family-based interventions (e.g., studies intervening
on parenting style, and on home availability of healthful food and opportunities
for physical activity).
- Test interventions with physicians and other healthcare providers
combined with community involvement (e.g., train physicians to screen,
nurses to be coaches and healthcare settings to refer to community resources).
- Test long-term effects of obesity prevention interventions on weight
and cardiovascular risk factors.
- Test effects of having single and multiple behavioral targets (e.g.,
intervening on a targeted food (e.g., fructose) vs. multiple foods;
dietary interventions with and without modifications in physical activity
and sedentary behaviors).
- Conduct studies that consider critical developmental periods of weight
gain.
- Test interventions that use novel theories beyond the models that
dominated the literature in the past 20 years.
- Conduct interventions in a variety of settings (e.g., home, child-care,
WIC, health-care settings).
Multi-level Multi-Component Interventions
(any age)
- Examine multi-level and multi-component community-based interventions
in multiple settings (e.g., schools, healthcare, home, community, built
environment, public policy, social marketing; diet, physical activity
behaviors).
- Test a multi-level comprehensive intervention targeting minority
population and low-income populations (e.g., culturally appropriate
ways to reach Latino, African American, Native American and Asian/Pacific
Islander children).
- Test interventions that use technology (e.g., internet, media, novel
electronic approaches) to influence behavior change.
- Develop and test interventions that can be effectively incorporated
into existing school and community infrastructures (e.g., curriculum,
physical activity, lunch modification) to maximize effectiveness and
minimize cost.
- Conduct intervention studies that address issues related to the interface between individual behaviors and
the environment.
Implementation, Dissemination, Translation,
Evaluation
- Identify and test approaches for community partnerships in dissemination
and implementation of evidence-based obesity prevention programs.
- Evaluate the effectiveness of existing promising programs (e.g., NIH
Ways to Enhance Children’s Activity and Nutrition (We CAN ))..
- Identify and test food marketing strategies.
Back to top
RECOMMENDATIONS
FOR RESEARCH IN CHILDHOOD OBESITY TREATMENT
MAJOR THEMES
Behavioral Approaches to Obesity Treatment
in Children (includes severely obese)
- Identify and test components of behavioral approaches for weight loss
in obese children (e.g., self-monitoring, goal setting; individual vs.
group sessions; technology including video games, telemedicine; parent,
child, and/or family as intervention targets).
- Identify and test components of behavioral approaches for weight control
or maintenance (not weight loss) in obese children.
- Identify and test diet and physical activity programs (e.g., dietary
and physical activity patterns, single dietary components such as fructose).
- Identify and test psychosocial influences on behavioral changes in
obese children.
Pharmacologic and Surgical Treatment of
Severe Obesity in Children
- Compare pharmacological agents, including off-label uses, or compare
surgical procedures versus pharmacologic agents for weight loss with
and without behavioral approaches.
- Test effects of different surgical procedures for weight loss in combination
with behavioral approaches and evaluate safety parameters (e.g., psychosocial
factors, height, and bone density).
- Test a stepped approach to obesity treatment (Expert Committee Recommendations).
- Identify biologic mechanisms of severe obesity to develop better therapeutic
targets (pharmacologic or surgical).
- Identify and test interventions in various settings for obesity treatment
(e.g., primary care and community linkages).
- Identify psychosocial aspects of obesity among the most obese children
in relation to pharmacologic and surgical treatments.
Health Systems and Primary Care Practices
- Identify and test models for delivering obesity care.
- Test approaches to changing behaviors of health practitioners.
- Identify and test approaches to translate and/or disseminate evidenced-based
therapies to primary care practices.
- Support research on macro-environment influences on healthcare delivery,
e.g., health policy, business models for practice, insurance coverage.
- Evaluate cost-effectiveness of primary care interventions.
Back to top
CROSS-CUTTING
RESEARCH RECOMMENDATIONS
Methodology
- Support methodological research on study designs and analytic approaches
(identify optimal study designs and analytic approaches for various
types of research questions, e.g., surgical and/or pharmacologic treatments,
multi-component and multi-level influences and interventions).
- Use appropriate study designs and methods including natural experiments,
quasi-experimental designs and randomized designs; develop time-sensitive
funding mechanisms for natural experiments.
- Standardize use of outcome measures to improve comparability of studies.
High-Risk Populations
- Study a diversity of high-risk subgroups including low-income families,
ethnically and socio-economically diverse populations, males and children
in rural communities as well as immigrants.
- Examine differences in treatment approaches or effects by age, race/ethnicity,
and socioeconomic status.
- Conduct environmental and policy intervention research to improve
access to healthy foods and opportunity for physical activity in low-income
communities.
Other Recommendations
- Identify biologic and behavioral mechanisms of obesity development,
including gene-environment interactions.
- Support long-term studies (~10 years) studies as well as short-term
“evidentiary” studies with intermediate outcomes.
- Support studies to improve technological approaches to prevent and
treat obesity (e.g., bioengineering approaches, internet, video, and
electronic medical records).
- Support translational research (Basic research ↔ clinical science
research ↔ clinical practice ↔ community/dissemination research).
- Measure cost-effectiveness of interventions.
- Consider using networks, consortia, Specialized Centers of Excellence,
partnerships with Clinical Translational Science Award (CTSA) or Academic
Research Centers.
Back to top
PRIORITIES FOR RESEARCH
- Obesity Prevention Interventions in Young Children: Test family-based
interventions to prevent excess weight gain in young children, including
high-risk populations such as minorities, children in low-income families,
children in rural communities, using multi-component and multi-level
approaches (e.g., home and school; community-school; home-community).
- Treatment interventions in obese children (includes severely obese):
Test weight loss interventions that use behavioral approaches (e.g.,
self-monitoring, goal setting; social support, stimulus control, cognitive
restructuring) with or without pharmacotherapy or surgical approaches,
and include multi-component multi-level approaches (e.g., healthcare
practice and home, healthcare practice and community, health care practice
and school).
- Health Systems and Primary Care Practices: Test models for delivering
obesity prevention and treatment to change behaviors of health practitioners
and to translate and/or disseminate evidenced-based therapies to primary
care practices.
- Implementation, Dissemination, Translation, Evaluation: Evaluate the
effectiveness of existing promising programs (e.g., NIH Ways to Enhance
Children’s Activity and Nutrition (WE CAN)).
- Methodology: Support methodological research on study designs and
analytic approaches (identify optimal study designs and analytic approaches
for various types of research questions, e.g., surgical and/or pharmacologic
treatments, multi-component and multi-level influences and interventions).
Back to top
References
- Institute of Medicine. Preventing Childhood Obesity, Washington, D.C:
National Academy Press, 2005.
- Ogden CL, Carroll MD, Curtin LR, McDowell MA, Tabak CJ, Flegal KM.
Prevalence of overweight and obesity in the United States, 1999-2004.
JAMA 2006; 295, (13): 1549-1555.
- Caballero B, Clay T, Davis SM, Ethelbah B, Rock BH, Lohman T, Norman
J, Story M, Stone EJ, Stephenson L, Stevens J; Pathways Study Research
Group. Pathways: a school-based, randomized controlled trial for the
prevention of obesity in American Indian schoolchildren. American Journal
of Clinical Nutrition, 2003 Nov;78(5):1030-8.
- Robert Wood Johnson Foundation. Childhood Obesity, 2007. http://www.rwjf.org/obesity
- Daniels SR, Arnett DK, Eckel RH, Gidding SS, Hayman LL, Kumanyika
S, Robinson TN, Scott BJ, St Jeor S, Williams CL. Overweight in children
and adolescents: pathophysiology, consequences, prevention, and treatment.
Circulation, 2005, 111 (15), 1999-2012.
- Din-Dzietham R, Liu Y, Bielo MV, Shamsa F. High blood pressure trends
in children and adolescents in national surveys 1963-2002. Circulation,
2007, 116:1488-1496.
- Lorch SM, Sharkey A. Myocardial velocity, strain, and strain rate
abnormalities in healthy obese children. J Cardiometabolic Syndrome,
2007, 2(1):30-34.
- Whitaker RC, Wright JA, Pepe MS, Seidel
KD, Dietz WH. Predicting obesity in young adulthood from childhood and
parental obesity. N Engl J Med. 1997, 25;337(13):869-73.
Finkelstein EA, Fiebelkorn IC, and Wang G. National medical spending attributable
to overweight and obesity: How much, and who’s paying? Health Affairs
(Millwood) Suppl. Web Exclusive (2003): W3-219-26. http://content.healthaffairs.org/cgi/reprint/hlthaff.w3.219v1
- Finkelstein EA, Fiebelkorn IC, and Wang G. State-level estimates of
annual medical expenditures attributable to obesity. Obesity Research,
2004,12;18-24.
- Wang G, Dietz WH. Economic Burden of Obesity in Youth Aged 7 to 17
years, 1979-1999, Pediatrics, 2002, 109, 5: E81.
- Woolford SJ, Gebremarian A, Clark SJ, Davis MM. Incremental hospital
charges associated with obesity as a secondary diagnosis in children.
Obesity 2007, 15 (7): 1895-901.
- Schonfeld-Warden N, Warden CH. Pediatric obesity: An overview of etiology
and treatment. Pediatr Clin North Am. 1997, 44(2):339-61.
- Katz DL, O’Connell M, Yeh M, Nawaz H, Njike V, Anderson LM, Cory S,
Dietz W. Public Health Strategies for Preventing and Controlling Overweight
and Obesity in School and Worksite Settings: A Report on Recommendations
of the Task Force on Community Preventive Services. MMWR, October 7,
2005 / 54(RR10);1-12.
- Summerbell CD, Waters E, Edmunds LD, Kelly S, Brown T, Campbell KJ.
Interventions for preventing obesity in children Cochran Database of
Systematic Reviews, Issue 3 Art. No.: CD001871. DOI: 10.1002/14651858.
CD001871.pub2, 2007.
- Flynn MAT, McNeil DA, Maloff B, Wu M, Ford, C Tough SC. Reducing obesity
and related chronic disease risk in children and youth: a synthesis
of evidence with ‘best practice’ recommendations. Obesity Reviews, 2006;
7(Suppl. 1), 7-66.
- Bluford DAA, Sherry B, Scanlon KS. Interventions to prevent or treat
obesity in preschool children: A review of evaluated programs. Obesity,
2007; 15(6):1356-1372.
- Stice E, Shaw H, Mati N. A meta-analytic review of obesity prevention
programs for children and adolescents: The skinny on intervention that
work. Pscyhological Bulletin, 2006, 132(5):667-691.
- Doak CM, Visscher RLS, Renders CM et al. The prevention of overweight
and obesity in children and adolescents: A review of interventions and
programs. Obesity Reviews, 2006, 7, 111-136.
- Robinson TN. Reducing children’s television, viewing to prevent obesity:
A randomized controlled trial. JAMA 1999; 282 (16): 1561-1567.
- Flores R. Dance for Health. Public Health Reports, 1995;110 (2):189-193.
- Gortmaker SL, Peterson K, Wiecha J, Soal Am, Dixit S, Fox MK, et al.
Reducing obesity via a school-based interdisciplinary intervention among
youth. Archives of Pediatrics and Adolescent Medicine, 1999; 153(4):409-418.
- Mueller MJ, I Asbeck, Mast M, Langnase K, Grund A. Prevention of obesity—more
than an intention. Concept and first results of the Kiel Obesity Prevention
Study (KOPS). International Journal of Obesity, 2001, 25, Suppl 1, S66-S74.
- Stevens J, Taber DR, Murray DM, Ward DS. Advances and controversies
in the design of obesity prevention trials. Obesity, 2007, 15(9):2163-70.
- Prochaska JO, Velicer WF. The Transtheoretical Model of Health Behavior
Change. Am J Health Promotion, 1997, (1):38-48.
- Becker MH. The Health Belief Model and Personal Health Behavior. Health
Education Monographs, 1974, 2 (4): 324-473.
- Bandura A. Social foundations of thought and action: Social Cognitive
Theory. Englewood Place, NJ, Prentice- Hall, 1986.
- Rosentock IM, Strecher VJ, Becker MH. Social Learning Theory and the
Health Belief Model. Health Education Quarterly, 15 (2) 173-183.
- Glanz K, Rimer BK, Lewis FM. Ed. Health Behavior and Health Education:
Theory, Research and Practice. San Francisco, CA, Jossey-Bass, 2002,
573pp.
- Resnicow K, Vaughan R. A chaotic view of behavior change: a quantum
leap for health promotion. International Journal of Behavioral Nutrition
and Physical Activity, 2006,12;3:25-30.
- Baranowski T. Crisis and chaos in behavioral nutrition and physical
activity. International Journal of Behavioral Nutrition and Physical
Activity, 2006, 14; 3:27.
- Baranowski T, Cullen KW, Nicklas T, Thompson D, Baranowski J. Are
current health behavioral change models helpful in guiding prevention
of weight gain efforts? Obesity Research, 2003, 11 Suppl: 23S-43S.
- Baranowski T, Lin L, Wetter DW, Resnicow K, Davis M. Theory as mediating
variables: Why aren't community interventions working as desired? Annals
of Epidemiology 1997; 7(S7):89-95.
- Saelens BE, Sallis JF, Nader PR, Broyles SL, Berry CC, Taras HL. Home
environmental influences on children's television watching from early
to middle childhood. J Dev Behav Pediatr. 2002, 23(3):127-32.
- Sallis JF, McKenzie TL, Conway TL, Elder JP, Prochaska JJ, Brown M,
Zive MM, Marshall SJ, Alcaraz JE. Environmental interventions for eating
and physical activity: A randomized controlled trial in middle schools.
American Journal of Preventive Medicine, 2003, 24 (3), 209-217.
- Kligerman M, Sallis JF, Ryan S, Frank LD, Nader PR. Association of
neighborhood design and recreation environment variables with physical
activity and body mass index in adolescents. Am J Health Promotion,
2007, 21(4):274-7.
- Kerr J, Rosenberg D, Sallis JF, Saelens BE, Frank LD, Conway TL. Active
commuting to school: Associations with environment and parental concerns.
Med Sci Sports Exerc. 2006, 38(4):787-94.
- Cooper AR, Andersen LB, Wedderkopp N, Page AS, Froberg K. Physical
activity levels of children who walk, cycle, or are driven to school.
Am J Prev Med. 2005, 29(3):179-84
- Frank L, Kerr J, Chapman J, Sallis J. Urban form relationships with
walk trip frequency and distance among youth. Frank L. Am J Health Promot.
2007, 21(4 Suppl):305-11.
- Jago R, Baranowski T, Baranowski JC, Cullen KW, Thompson D. Distance
to food stores & adolescent male fruit and vegetable consumption: mediation
effects. International Journal of Behavioral Nutrition and Physical
Activity, 2007,13;4:35.
- Murray DM, Varnell SP, Blitstein JL. Design and analysis of group-randomized
trials: a review of recent methodological developments. Am J Public
Health, 2004, 94(3):423-32.
- Varnell SP, Murray DM, Janega JB, Blitstein JL. Design and analysis
of group-randomized trials: a review of recent practices. Am J Public
Health, 2004, 94(3):393-9.
- Sung NS, Crowly WF, Salber P, Sandy L, Sherwood LM et al. Central
challenges facing the national clinical research enterprise. JAMA 2003,
289 (10), 1278-1287.
- Glasgow RE, Emmons KM. How can we increase translation of research
into practice? Types of evidence needed. Annu Rev Public Health, 2007;
28:413-33.
- Expert Committee Recommendations on the Assessment, Prevention, and
Treatment of Child and Adolescent Overweight and Obesity, January 25,
2007. http://www.ama-assn.org/ama1/pub/upload/mm/433/ped_obesity_recs.pdf
- Freedman DS, Mei Z, Srinivasan SR, Berenson GS, Dietz WH. Cardiovascular
risk factors and excess adiposity among overweight children and adolescents:
the Bogalusa Heart Study. Journal of Pediatrics, 2007, 150(1):12-17.
- Epstein LH, Valoski A, Wing RR, McCurley J. Ten-year outcomes of behavioral
family-based treatment for childhood obesity. Health Psychology, 1994,13(5):373-83
- Epstein LH, Valoski AM, Kalarchian MA, McCurley J. Do children lose
and maintain weight easier than adults: a comparison of child and parent
weight changes from six months to ten years. Obesity Research, 1995,
3(5):411-417.
- The Chronic Care Model. http://improvingchroniccare.org/index.php?p=The_Chronic_Care_Model&s=2
- O’Brien H et al., Identification, evaluation and management of obesity
in an academic primary care center. Pediatrics 2004; 114:e154-e159.
- Summerbell CD, Ashton V,, Campbell KJ, Edmunds L, Kelly S, Waters
E. Interventions for treating obesity in children (Review). Cochrane
Database of Systematic Reviews, 2003, (3) Art No. CD001872. DOI 1002/1451858.
CD001872.
- Epstein LH, Paluch RA, Gordy CC, Dorn J. Decreasing sedentary behaviors
in treating pediatric obesity. Arch Pediatr Adolesc Med., 2000,154(3):220-6.
- Golan M, Kaufmann A, Shahar DR. Childhood obesity treatment: targeting
parents exclusively v. parents and children. British Journal of Nutrition,
2006:95, 1008-1015.
- Kitzmann KM, Beech BM. Family-based interventions for pediatric obesity:
methodological and conceptual challenges from family psychology. J Fam
Psychol. 2006, 20(2):175-89.
- Wing RR, Hill JO. Successful weight loss maintenance. Annual Review
of Nutrition, 2001;21:323-41.
- Chanoine JP, Hampl S, Jensen C, et al. Effect of orlistat on weight
and body composition in obese adolescents: a randomized controlled trial.
JAMA, 2005; 293(23):2873-83.
- McDuffie JR, Calis KA, Uwaifo GI, Sebring NG, Fallon EM, Hubbard VS,
Yanovski JA. Three-month tolerability of orlistat in adolescents with
obesity-related comorbid conditions. Obesity Research, 2002, 10(7):642-50.
- Berkowitz RI, Wadden TA, Tershakovec AM, Cronquist JL. Behavior therapy
and sibutramine for the treatment of adolescent obesity: a randomized
controlled trial. JAMA, 2003, 289(14):1805-12.
- Berkowitz RI, Fujioka K, Daniels SR, Hoppin AG, Owen S, Perry AC,
Sothern MS, Renz CL, Pirner MA, Walch JK, Jasinsky O, Hewkin AC, Blakesley
VA; Sibutramine Adolescent Study Group. Effects of sibutramine treatment
in obese adolescents: a randomized trial. Ann Intern Med, 2006,18;145(2):81-90.
- Godoy-Matos A, Carraro L, Vieira A, et al. Treatment of obese adolescents
with sibutramine: a randomized, double-blind, controlled study. J Clin
Endocrinol Metab., 2005; 90(3):1460-5.
- Davis MM, Slish K, Chao C, Cabana MD. National Trends in Bariatric
Surgery, 1996-2002. Arch Surg., 2006;141:71-74.
- Inge TH, Krebs NF, Garcia VF, Skelton JA, Guice KS, Strauss RS et
al. Bariatric surgery for severely overweight adolescents: Concerns
and recommendations. Pediatrics, 2004, 114 (1), 217-223.
- Kalra M, Inge T. Effect of bariatric surgery on obstructive sleep
apnoea in adolescents. Paediatr Respir Rev., 2006, 7(4):260-7.
- Harvey EL, Glenny AM, Kirk SF, Summerbell CD An updated systematic
review of interventions to improve health professionals' management
of obesity. Obes Rev. 2002, 3(1):45-55.
- Kumanyika S, Grier S. Targeting interventions for ethnic minority
and low-income populations. Future of Children, 2006, 16(1):187-207.
- Wang Y, Kumanyika S. Descriptive Epidemiology of Obesity in the United
States. Chapter 3, in Kumanyika SK, Brownson RC. (Eds.). Handbook of
Obesity Prevention. New York: Springer Publishing Co., 2007, pp. 45-71.
- Kumanyika SK. Environmental influences on childhood obesity: Ethnic
and cultural influences in context. Physiol Behav. 2008 22;94(1):61-70.
- Kumanyika SK, Whitt-Glover MC, Gary TL, Prewitt, TE, Odoms-Young AM,
Banks-Wallace J, Beech BM, Hughes Halbert C, Karanja N, Lancaster KJ,
Samuel-Hodge CD. Expanding the obesity research paradigm to reach African
American communities. Preventing Chronic Diseases, 2007; 4(4). http://www.cdc.gov/pcd/issues/2007/oct/07_0067.htm.
- Herbert A, Gerry NP, McQueen MB, Heid IM, Pfeufer A, Illig T, Wichmann
HE, Meitinger T, Hunter D, Hu FB, Colditz G, Hinney A, Hebebrand J,
Koberwitz K, Zhu X, Cooper R, Ardlie K, Lyon H, Hirschhorn JN, Laird
NM, Lenburg ME, Lange C, Christman MF. A common genetic variant is associated
with adult and childhood obesity. Science, 2006, 312(5771):279-83.
- Loos RJ, Barroso I, O'rahilly S, Wareham NJ. Comment on "A common
genetic variant is associated with adult and childhood obesity". Science,
2007, 12;315(5809):187.
- Collins LM, Murphy SA, Strecher V. The Multiphase Optimization Strategy
(MOST) and the Sequential Multiple Assignment Randomized Trial (SMART):
New methods for more potent e-health interventions. American Journal
of Preventive Medicine, 2007, 32, S112-S118.
- Rivera DE, Pew MD, Collins LM. Using engineering control principles
to inform the design of adaptive interventions. Drug and Alcohol Dependence,
2007, 88, S31-S40.
- Murphy SA, Lynch KG, McKay JR, Oslin D, TenHave T. Developing adaptive
treatment strategies in substance abuse research. Drug and Alcohol Dependence,
2007, 88, S24-S30.
- A Collins LM, Murphy SA, Bierman KL. Conceptual framework for adaptive
preventive interventions. Prev Sci., 2004, 5(3):185-96.
- Li R, Root T L, Shiffman S. A local linear estimation procedure for
functional multilevel modeling. In T. A. Walls & J. L. Schafer (Eds.).
Models for intensive longitudinal data (pp. 63-83). New York: Oxford
University Press, 2006.
- Graham JW, Taylor BJ, Olchowski AE, Cumsille PE. Planned missing data
designs in psychological research. Psychological Methods, 2006, 11,
323-343.
Back to top
May 2008
|